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58 Cards in this Set
- Front
- Back
What do the follicle cells produce?
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thyroid hormones
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What are the thyroid hormones?
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T₃ and T₄ (commonly called thyroxine)
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What are the effects of thyroid hormone?
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Primary effect — ↑ in metabolic rate
• ↑ O₂ consumption • produces heat as cell consumes more energy |
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To meet this increased metabolic demand and ensure blood flow...
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• ↑ heart rate and contraction strength (~ ↑ BP)
• ↑ respiratory rate • ↑ carbohydrates, fat & protein metabolism (need fuel) Important for nervous system & skeletal development, maturation of reproduction system and growth (works with GH) |
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Thyroid Hormone Regulation
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Negative feedback loop
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Parafollicular cells (C cells) produce the hormone _____.
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calcitonin
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What is the function of calcitonin?
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lowers blood Ca²+ levels
• anatagonist to parathyroid hormone (PTH) |
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Parathyroid Gland
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secretes parathyroid hormone (PTH)
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Parathyroid hormone
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raises Ca²+ levels in blood
• ↓ Ca²+ triggers PTH release • ↑ Ca²+ inhibits PTH release |
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Control of Hormone Release
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Humoral Stimuli: secretion of hormones in direct response to changing blood levels of ions and nutrients
Example: Ca²+ concentration in blood • ↓ Ca²+ in blood stimulates parathyroid glands to secrete PTH (parathyroid hormone) • PTH causes Ca²+ to ↑ ... and stimulus is removed |
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Adrenal (Suprarenal) Glands
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Structurally & functionally they are 2 glands in 1
• adrenal cortex • adrenal medulla |
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adrenal cortex
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glandular tissue
• synthesizes & release steroid hormones called corticosteroids 1. Mineralcorticoids (aldosterone) 2. Glucocorticoids (cortisol) 3. Androgens (sex steroids) |
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adrenal medulla
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neural tissue that acts as part of SNS
• synthesizes & releases catecholamine hormones 1. Epinephrine 2. Norepinephrine |
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What are the three layers of the Adrenal cortex?
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1. Zona glomerulosa
2. Zona fasiculata 3. Zona reticularis |
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Zona glomerulosa
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mineralocorticoids (cheifly aldosterone)
• promote Na+ retention and K+ excretion by kidneys ∙ removes Na+ from urine forming in kidneys & returns it to the blood ∙ exchanges K+ for Na+ at kidneys; K+ is excreted in urine |
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Mineralcorticoids
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regulate mineral & water balance
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Aldosterone
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most important mineral corticoid
Aldosterone secretion is stimulated by: • high blood K+ • low blood Na+ • ↓ blood volume or pressure Where Na+ goes, water follows: aldosterone also helps regulate blood volume & pressure |
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Zona fasiculata
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glucocorticoids (chiefly cortisol)
Glucocorticoids - help body resist stress or intermittent food uptake by: • keeping blood glucose levels relatively constant • regulated by negative feedback Rising cortisol levels inhibit anterior pituitary (ACTH) & hypothalamus (CRH) |
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Glucocorticoids
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Glucocorticoids - help body resist stress or intermittent food uptake by:
• keeping blood glucose levels relatively constant • regulated by negative feedback |
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What is the stimuli and effect of the zone fasiculata
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Stimuli: stress or hypoglycemia cause CRH release
Effect: cortisol released to ↑ plasma levels of glucose, fatty acids & amino acids: 1) glucogenesis - glucose synthesis from fats and proteins in liver • especially between meals • glucose sparing effect - "save" glucose for brain 2) mobilize fatty acids from adipose tissue (for ATP production) 3) break down stored proteins (provides free aa for repair/enzymes) |
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gluconegenesis
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glucogenesis - glucose synthesis from fats and proteins in liver
• especially between meals • glucose sparing effect - "save" glucose for brain |
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Zona reticularis
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gonadocorticoids (chiefly androgens)
Gonadocorticoids (principally weak androgens) Weak androgens are converted into: • testosterone (males) • estrogens (females) ∙ Gonadocorticoids produced by adrenal gland = insignificant compared to amount from gonads |
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What is the effect and regulation of the zone reticularis?
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Effect: onset of puberty, appearance of secondary sex characteristics (7-13 years)
Regulation: release seems to be stimulated by ACTH (but gonadocorticoids do not seem to exert feedback inhibition on ACTH) |
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Adrenal medulla
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• secretory activities controlled by sympathetic division of ANS
• Chromaffin cells - produce epinephrine (adrenaline) & noreinephrine Secretion of these hormones cause: 1) Blood glucose levels to rise 2) Blood vessels constrict 3) Blood diverted to the brain, heart, and skeletal muscle |
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Secretion of chromaffin cells cause:
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1) Blood glucose levels to rise
2) Blood vessels constrict 3) Blood diverted to the brain, heart, and skeletal muscle |
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Chromaffin cells produce
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epinephrine (adrenaline) & norepinephrine
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What type of organ in the pancreas? (Endocrine and/or Exocrine)
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endocrine and exocrine organ
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Exocrine (pancreas)
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acinar cells produce enzyme-rich alkaline juice used for digestion
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Endocrine (pancreas)
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pancreatic islets produce hormones
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Pancreatic islets (islets of Langerhans) contain:
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Alpha (α) cells and Beta (β) cells
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Alpha (α) cells
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produce glucagon
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Beta (β) cells
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produce insulin
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What is the target, effect and regulation of glucagon?
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Hyperglycemic agent: increases blood glucose
Target: liver Effect: •Glycogenolysis • Gluconeogenesis Glucose then enters the blood Regulation: stimulated by falling blood glucose |
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glycogen
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short-term energy storage of glucose
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glycogenolysis
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breakdown of glycogen to glucose
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gluconeogenesis
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synthesis of glucose
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What is the target, effect and regulation of insulin?
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Hypoglycemic agent - lowers blood glucose levels
Target: most cells of the body Effect: • Enhances transport of glucose into body cells • Stimulates glycogen formation at liver Glucose then leaves the blood Regulation: stimulated by rising blood glucose |
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Fill in the numbers
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1. insulin
2. insulin 3. glucose 4. glycogen 5. glucagon 6. glucagon 7. glycogen |
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What is the function and stimulus of glucagon?
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Glucagon: α cells
Function: ↑ blood glucose concentration Stimulus: low blood glucose concentration "When glucose is gone" |
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What is the function and stimulus of insulin?
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Insulin: β cells
Function: ↓ blood glucose concentration Stimulus: high blood concentration |
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What is diabetes mellitus?
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disorder results from insulin deficiency or resistance → leading to high blood glucose
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What is diabetes insipidus?
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disorder caused by hypo secretion of ADH (disables water conservation at kidneys)
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Explain Diabetes Mellitus Type 1:
What is the Onset, Prevalence, β cells, treatment? |
Onset: Juvenile onset
Prevalence: 5-10% Cause: ~ auto-immune response β cells: Immune system destroys β cells → failure to produce insulin Treatment: |
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Explain Diabetes mellitus Type 2:
What is the Onset, Prevalence, Cause, β cells, Treatment? |
Onset: Adult Onset
Prevalence: 90-95% Cause: Linked to sedentary lifestyle, poor diet, obesity β cells: Treatment: |
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Pineal Gland
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• Small gland hanging from roof of 3rd ventricle of brain
• Pinealocytes secrete melantonin |
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What is melantonin?
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• involved in day/night cycles (hight at night; low in day)
• physiological processes that have rhythmic variations (body temperature, sleep, appetite) |
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What are female gonads?
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Paired ovaries in abdominopelvic cavity produce estrogens and progesterone
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What is the function of estrogens and progesterone?
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• maturation of reproductive organs
• appearance of secondary sexual characteristics • breast development and cyclic changes in uterine mucosa |
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What are male gonads?
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testes located in an extra-abdominal sac (scrotum) produce testosterone
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What is the function of testosterone?
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• initiates maturation of male reproductive
• causes appearance of secondary sexual characteristics and sex drive • necessary for sperm production • maintains sex organs in their functional state |
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What are some other hormone producing tissues?
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1. adipose tissue
2. thymus 3. heart 4. kidneys 5. digestive system |
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What two peptide hormones does adipose tissue produce?
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Leptin and Resistin
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What is leptin?
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feedback control for appetite
• when you eat → leptin is released (= feel full) • some obese individuals appear to have defective leptin receptors |
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What is resistin?
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• decreased insulin sensitivity of body cells (insulin antagonist)
• was thought could be "missing link" between obesity and type II Diabetes |
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What is the thymus?
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produces hormone thymosin
• essential for T lymphocyte development & activity |
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What hormone(s) is the heart responsible for producing?
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produced natriuretic peptides (ANP/atrial NP & BNP/brain NP)
• both reduce blood volume & blood pressure |
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What hormone is the kidney responsible for producing?
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erythopoietin (EPO) - red blood cell production
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What hormones is the Digestive System responsible for producing?
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gastrin - coordinates digestive activities
secretin - coordinates digestive activity CCK - coordinates digestive activities |